Wind turbines show up on radar as tornadoes

Wind turbines in Iowa and across the country are showing up on weather radar and looking like tornadoes. Recently, the Des Moines National Weather Service office received a call from an emergency worker who mistook a wind turbine for a twister on doppler radar.

Meteorologist Jeff Johnson says only an amateur would make that mistake. “Wind turbines can produce a false radar echo and you can see it on reflectivity on the internet,” Johnson said. “They look like splotches, they may look like a storm, but to a trained eye it’s obviously what it is – it’s not a meteorological echo.”

But, elsewhere in the country there have been discussions about shutting down wind farms prior to bad storms. In Kansas, a computer program misidentified a wind turbine on radar and mistakenly issued a tornado warning. A meteorologist quickly called off the alert.

“To the lay person out there looking at radar data…a lot of things look false,” Johnson said. “You can have bird interference that shows up on doppler radar that shows a signature that may be confused with something that isn’t there.” Weather radar recognizes motion to warn of storms, and there’s no way to filter out the spinning blades.

Johnson says the National Weather Service is working with the wind power industry so new wind farms might be located to minimize interference with weather radar.